Question

1. What is screw pump?

2. working principle of screw pump.

3. screw pump test rig

4. procedure

5. general use

6. identify its accuracy, precision and time respond in getting a reading.

7. the advantage and disadvantage of screw pump.

Answer 1

1. A screw pump is a type of rotary pump which is equipped with screws that mesh together and rotate within a cylindrical cavity or liner. The fluid enters from the suction side of the pump and moves linearly along these intermeshing screws to the discharge side of the pump. The clearances between the screws and the liner are very small hence the fluid gains pressure while moving through the pump.

2.The screw pump working principle involves the rotary action of screw rotors. As depicted in the double screw pump , the pump works by:
- Drawing liquid into spaces between threads at suction end
- Axially carrying the liquid that is trapped in the spaces between the threads
- Discharging the liquid at the outlet

3. it is used to study the differnt characteristic of the the screw pump.

4.STARTING PROCEDURE: 1. Clean the apparatus and make tanks free from dust. 2. Close the drain valves provided. 3. Fill Sump tank .th with clean water and ensure that no foreign particles are there. 4. Open flow control valve given on the water discharge line and control valve given on suction line. 5. Ensure that all ON/OFF switches given on the panel are at OFF position. 6. Set the speed of pump with the help of 3 speed step cone pulley. 7. Now switch ON the main power supply and switch ON the Pump. 8. Operate the flow control valve to regulate the flow of water discharged by the pump. 9. Operate the control valve to regulate the suction of the pump. 10. Record discharge pressure by means of pressure gauge, provided on discharge line. 11. Record suction pressure by means of vacuum gauge, provided at suction of the pump. 12. Note down the time required for 10 pulses with the help of stop watch to calculate the power consumption. 13. Note down the RPM. 14. Measure the flow of water, discharged by the pump, using stop watch and measuring tank. 15. Repeat the same procedure for different pressure head. 16. Repeat the same procedure for different RPM with the help of step cone pulley.

CLOSING PROCEDURE: 1. When experiment is over, properly open the gate valve provided on discharge line. 2. Switch OFF the pump first. 3. Switch OFF power supply to panel (MCB).